Pantograph engraving tool



Nov. 25, 1924. 1,516,897

C- D. TUSKA ET AL PANTOGRAPH ENGRAVING TOOL Filed June 13. 1923 PatentedNov. 25, 1924.

UNITED STATES PATENT OFFICE.

CLARENCE D. TUSKA AND PERCIVAL H. SPENCER, OF HARTFORD, CONNECTICUT, AS-SIGNOBS TO THE C. TUSKA COMPANY, A CORPORATION OF CONNECTICUT.

PANTOGBAPH ENGRAVING TOOL.

Application filed June 13, 1923. Serial No. 645,100.

To all whom it may concern:

Be it known that Cnannxcn D. TUSKA and PERCIVAL H. SPENCER, citizens ofthe United States, residing at Hartford, in the county of Hartford andState of Connecticut, have invented new and useful Improvements in Pantoaph Engraving Tools, of which the fo lowing is a specification.

This invention relates to an engraving device and more particularly to adevice wherein the principle of a pantograph is employed for the purposeof reproducing from a suitable pattern, letters, figures, etc.,' similarcharacters of smaller size on the object to be en raved.

One object 0 the invention is to provide a simple and eflicientarrangement where by the en raving of accurate characters on very harsubstances, such as panels for radio cabinets, is accomplished within aminimum space of time and from patterns of large size thereby reducingthe perceptible error.

Another object is to construct a device employin a comparatively largesize pattern invo ving a considerable distance between the engravingtool and tracing point wherein the working or engraving tool may becontrolled from a point in proximity to the tracing point.

Another object is to provide a device of .this character wherein the deth of cut of the working or engraving too is regulated by a supportadjacent to the workin tool contacting with the surface on whifii theengraving is to be done whereb the depth of cut on uneven or inclined suaces is uniform. v

With these and other objects in view the invention consists in thevarious features of construction and in the combination and arrangementof parts, hereinafter described and claimed, the advantages of whichwill be obvious to those skilled in the art.

In the accompanying drawin Fig. 1 is a plan view of the fe vice;

Fig. 2 is an enlarged side view of a portion of the tool arm andmountings there- Fig. 3 is a detail side view showin the base andsupporting arm thereon; an

Fig. 4 is a detail view of the lever arm and mounting looking to theleft in Fig. 2.

Referring to the drawings, 11 represents means of a bearing 33. The arm4 is preferably mounted on the shaft 32 by means of a ball bearing (notshown) and the point on the arm 4 where bearing 33 is located willprovide for the desired reduction of the pattern taken in connectionwith the various other parts of the device to be hereinafter described.This arm 4 may be made of light but strong material but is so designedas to be in the nature of a truss bar as shown. At one end of the arm 4there is provided a yoke or forked construction 34 in which one end ofthe tool guiding arm 7 is swivelly connected by means of a stub shaft 35passing therethrough. This swivel connection is preferably of a ballbearing type but may be of the usual pin and socket construction asshown in the drawing. This arm 7 may also be made of light but strongmaterial such as aluminum. At the other end of arm 4 there is pivotallyconnected thereto the tracing arm 1 at a suitable point intermediate theends of the latter by means of stub shaft 36. This may also be a ballbearing type connection. At one end of the tracing arm 1 is the tracingpoint 2 and the other end is connected to the other end of the toolguiding arm 7 by a tie arm 3 having pivotal connections 5 and 8therewith. It will be observed that the arms 1, 3, 4 and 7 are connectedin the usual parallelogram form for pantograph action, the ratio ofreduction between the tracing point and the working point beingpreferably about 7 to 1. At a suitable point on the tool guidin arm 7there is provided a boss 38 in whici is located a heavy bearing 12.Through this bcarin 12 extends a shaft 13 positioned therein y means ofball bearings 66 and having a pulley 14 fixed at its u per end andprovided with a socket in its ower end to fixedly receive an engravingtool 15. The up er end of the bearing 12 is provided wit fi a fixedknurled ring nut or washer 16 for a purpose to be presently described.At the lower end of bearing 12 adacent the outer edge thereof andscrewthreaded therein is a bearing su port or stop 17 provided at itslower en with a work follower 18 for contact with the work to be enraved and having a knurled portion 19 For adjusting the same. A suitableknurled lock nut 20 is provided for securing the stop 17 in a desiredposition after being adjusted by means of manipulating the knurledportion 19.

On the upper edge of the arm 7 on one side of bearing 12 is a smallrecessed boss 21 through which a shaft 22 extends having a lever arm 23at its outer end. The inner end of the shaft 22 is rovided with aneccentric stud 24. extending beneath the ring nut or washer 16 to raiseor lower said bearing 12 when said arm 23 is operated. To the upper endof lever arm 23 there is connected a Bowden wire 27 or other similarmeans which runs through clamps 28 on arms 7, 4, and 1 to a pointadjacent the tracing point 2. By meansof a pushing or pulling movementon this Bowden wire 27 the lever arm 13 is rocked through an angle of 90which in turn by means of the cocentric stud 24 will elevate or lowerthe bearing 12 and engraving tool 15.

The lever arm 23 and eccentric stud 24 are so positioned relative toeach, other that when the lever arm 23 is in the position as shown inFig. 4 the bearing 12 is not held in an elevated position but issupported upon the work by the stop 17. When the lever arm 23 is rockedto the left through an angle of 90 by means of the Bowdcn wire 27, theeccentric stud 24 engages the under side of the washer 16 and raises thebearing. The 90 movement of the lever arm 23 brings the eccentric stud24 a little beyond the line of centers, thereby providing a releasableholding means for the lever. There is also provided a stop 37 on thelower end of lever arm 23 to limit the swinging action of the lever inthis direction. On the opposite side of the bearing 12 on arm 7 there islocated a shaft 39 having a pair of idler ulleys 25 thereon. The shaftis supporte on a pair of lugs 26 fixed to arm 7. 9 represents an endlessbelt which connects a motor (not shown) for supplying power to rotatethe engraving tool 15.

There is thus provided a control over the engravin tool which isadjacent the tracing point. is is especially desirous where theproportions of the arms 4 and 7 and arms 1 and 3 are large as it enablesthe operator of the tracing point to work continuously without movingaround to elevate the engraving tool every time he moves the tracingpoint out of the master characters. The bearing 12, by being slidablymounted in the arm 7 has a floatlngup and down movement and the tool 15,being fixed in the rotating shaft 13, which in turn is positioned in thehearing 12, also has this floating up and down movement. The stop 17, byriding in contact with the work to be engraved, acts as a work followerand controls the vertical floating movement of the bearing and tool. Itwill be observed that by means of this arrangement the stop 17 willlimit the depth of cut of the revolving tool 15 and maintain the samedepth of cut over any art of the work surface whether that sur ace islevel or not. This stop 17 is also provided with means to adjust samewith respect to the engraving tool 15 so that the depth of cut may beregulated to any desired depth.

I have also provided means to index the stop 17 so that Where theengraving is near or at the outside edges of the engraved object thework follower 18 will remain in contact with the surface of the engravedobject. This means comprises preferably a plurality of indentations 29on the upper cylindrical surface of the bearing 12 coactin with a springpressed plunger 30 locate in a socket 31 on top of arm 7 closelyadjacent to the hearing. The indentations 29 are of such a shape thatthe end of the plunger 30 will yieldingly retain the bearing in fixedposition but will allow the bearing to manually be turned to positionthe work follower 18 in any desired location around the axis of theengraving tool.

While I have disclosed a preferred embodiment of my device it isunderstood that the scope of the invention is defined by the appendedclaims:

1. A pantograph engraving device comprising in combination, a toolguidin arm, a weighted non-rotating bearing slldably mounted in said armfor a floatin up and down movement, an engraving too revolvably mountedin said bearing and carried vertically therewith, a tracing arm having atracing point remote from said engraving tool and means acting on saidvertically movable bearing for elevating and lowerin the same with saidengraving tool sai means being operable from the proximity of saidtracing point.

2. A 'pantograph engraving device comprising in combination, a toolguiding and supporting arm, a weighted bearin slidably mounted in saidarm for up an down movement, an engraving tool revolvably mounted insaid bearing and movable vertically therewith, a tracing arm having atracing point remote from said en aving tool, a stop, on said bearingfor limiting the depth of cut of said engraving tool and means forelevating and lowering said engraving tool operable from the proximityof said tracing point.

3. A pantograph engraving device comprisin in combination, a tool guidinarm, a Wei fined bearing slidably mounted 1n said arm or a floating upand down movement, an engraving tool revolvably mounted in said bearingand movable vertically therewith, a tracing arm having a tracing point,

an adjustable stop on said bearin and adapted to ride upon the work toengraved for regulating the depth of cut of said engraving tool.

4. A pantograph engravin device comprising in combination a too guidingand supporting arm, a weighted bearin slidably mounted in said arm forup an down movement, an engraving tool revolvabl mounted in said bearingand movable vertically therewith, a tracing arm having atracing pointremote from said engraving tool, a stop on said bearing for limiting thedepth of cut of said engraving tool, means for indexing said step aboutthe vertical axis of said bearing and means for elevating and loweringsaid engraving tool operable from the proximity of said tracing point.

5. A pantograph engraving device comprising, in combination, a tracingarm havmg a tracing point, a tool guiding arm, a rotating tool carriedin said guiding arm arran ed for a floating vertical movement and a workfollower separate from said tool and arranged to ride in contact withthe work to be engraved for controlling the vertical floating movementof said tool.

6. A pantograph engraving device comrising, in combination a tracing armhavmg a tracing point, a tool guidm arm, a rotating tool carried in saidgui mg arm remote from said tracing point and arranged for a floatingvertical movement, a work movement of said tool and means for elevatingsaid tool irom said work operable from the proximity of said tracingpoint. 7. A pantograph engraving device comprising, m combination, atracing arm havmgatracingpoingatoolguidmgarm,a rotating tool carried insaid guiding arm ared for a floating vertical movement, a followerseparate from said tool and to ridein contact with the work to beengraved for controlling the vertical floatmovemeniipf tlcliol, and1111188118 for a ustmg sai wor o ower wit respect to said tool toregulate the depth of cut of said tool;

A pantograph engraving device comprising, in combination, a tracing armhavmgatracingpoingatoolguidmgarm,a rotating tool carried in said idingarm arranged for a floating vertica movement and a work followerseparate from and closely adjacent to said tool and arranged to ride incontact with the work to be engraved for controlling the verticalfloating movement of said tool.

In testimony whereof we have alfixed our Letters DISCLAIMER.

l,515,897.01armce D. Tuaka and Percival H. Spencer, Hzrtforid, Conn. PM

omrn Emnuwnm Toom. Pahentdzted Nbyember 25, 1994. Disclaimer filed May28, 1925, by the assignee, The D. Tuslp 0mg. Hamlg entars thisdisclaimer to my interpmhtionof dlims 5, 7, gm], 8 of szid dent in whichthe'phraae, in each of said china, 1 l'flating tool carried in said ilirm arranged for a. floating movement does not mean that sai rotatingtpol is capable of a floating vertical movement in said guiding armand-relating thereto.

[Oficial Gazette Jam 88, 1926.]

